Recycle bin for tenants

In addition to the recycle bin for databases, tables, and indexes, OceanBase Database also provides a recycle bin for tenants.

The system tenant will not be dropped, and the recycle bin for tenant is managed by the system tenant by using commands.

Objects in the recycle bin for tenants are available only to the system tenant.

Notes:

• The DROP TENANT command converts a tenant name to the uniform format in the recycle bin. The space occupied by the tenant is not released, but a new connection cannot be established to the tenant.

• The FLASHBACK command uses the original tenant name or the tenant name in the recycle bin. The tenant name in the recycle bin is globally unique and therefore can identify the tenant to be restored. If multiple tenants have the same original name, the last tenant moved to the recycle bin is to be restored.

• The PURGE TENANT command can also use the original tenant name or the tenant name in the recycle bin. Unlike FLASHBACK, when multiple tenants have the same original name, the PURGE TENANT command deletes the first tenant moved to the recycle bin.

View the recycle bin

You can run the SHOW RECYCLEBIN command under the system tenant to view its recycle bin.

Example:

obclient> SHOW RECYCLEBIN;
+--------------------------------+----------------+----------+----------------------------+
| OBJECT_NAME                    | ORIGINAL_NAME  | TYPE     | CREATETIME                 |
+--------------------------------+----------------+----------+----------------------------+
| __recycle_$_1_1600136460199936 | wendo_table    | TABLE    | 2020-09-15 10:21:00.207886 |
| __recycle_$_1_1600136479664128 | wendo_database | DATABASE | 2020-09-15 10:21:19.664534 |
| __recycle_$_1_1600135793000960 | mysql          | TENANT   | 2020-09-15 10:23:25.773877 |
+--------------------------------+----------------+----------+----------------------------+
3 rows in set (0.21 sec)

OBJECT_NAME indicates the name in the recycle bin, and ORIGINAL_NAME indicates the original name.

In this example, mysql is a tenant object in the recycle bin.

Enable and disable the recycle bin

You can run the SET command under the system tenant to enable or disable its recycle bin.

Examples:

• Enable the recycle bin

  obclient> SET GLOBAL recyclebin=true;
  Query OK, 0 rows affected (0.01 sec)
  

• Disable the recycle bin

  obclient> SET GLOBAL recyclebin=false;
  Query OK, 0 rows affected (0.01 sec)
  

Restore objects from the recycle bin

By default, when the recycle bin is enabled for the system tenant, the DROP TENANT command moves the specified tenant to the recycle bin. You can run the FLASHBACK command to restore the tenant from the recycle bin.

Examples:

• Restore tenant_name from the recycle bin of the system tenant

  obclient> FLASHBACK TENANT <tenant_name> TO BEFORE DROP;
  

• Restore tenant_name from the recycle bin of the system tenant and rename it new_tenant_name

  obclient> FLASHBACK TENANT <tenant_name> TO BEFORE DROP RENAME TO <new_tenant_name>;
  

Purge the recycle bin

You can run the PURGE command under the system tenant to permanently delete the objects in the recycle bin.

• Purge tenant_name from the recycle bin

  obclient> PURGE TENANT tenant_name;
  

• Purge all objects from the recycle bin

  obclient> PURGE RECYCLEBIN;
  

  Note

  Constraints for the primary/standby cluster configuration

  • You cannot run the DROP TENANT, DROP TENANT FORCE, DROP TENANT PURGE, FLASHBACK TENANT, or PURGE TENANT command for a standby cluster. All these operations must be synchronized from the primary cluster.

  • You can run the PURGE RECYCLEBIN command for a standby cluster, but it does not delete tenants from the recycle bin.